When molecules move from a higher concentration to a lower concentration, it is known as

146.6 grams

Step-by-step explanation:

We have been given an element with Mass 630 grams decays by 18.8% per minute.

We will use exponential decay function to solve our given problem.

, where,

y = Final amount,

a = Initial amount,

r = Rate of decay in decimal form,

x = Time.

Substitute the given values:

Therefore, 146.6 grams of the element is remaining after 7 minutes.